Around 1000 BC, Native peoples began systematically mining minerals that naturally form on cave walls, like gypsum and mirabilite. Investigators have documented this mining throughout Mammoth Cave and in other Kentucky caves. Mineral mining evidence includes battering marks on cave walls, mussel shell scrapers/spoons, limestone hammerstones, and battering and ledge gypsum mining.
Native groups could have used gypsum as paint. Mirabilite has definite medicinal properties: when taken orally, it serves as a laxative. Its salty taste also means Native peoples may have used it as a seasoning and as a food preservative. Men, who probably made up the majority of miners, also may have held ceremonies within the cave for young boys coming-of-age.
After 200 BC, Native cave mining and exploration declined. This may reflect changes in Native beliefs and traditions.